Outgoing Senator David Leyonhjelm has failed at a second attempt to have Greens senator Sarah Hanson-Young's defamation case against him thrown out of court.
Senator Leyonhjelm has been ordered to pay Ms Hanson-Young's legal costs incurred during the appeal, which Ms Hanson-Young's lawyer Rebekah Giles estimates will be up to $100,000.
The crossbencher is being sued by Senator Hanson-Young over comments he made on various media outlets in June and July last year.
In interviews on Sky News, 3AW and the ABC's 7.30 program he justified comments he made earlier in parliament that Senator Hanson-Young should "stop shagging men".
Senator Hanson-Young claims she was portrayed as a hypocrite and misandrist which is the basis for the defamation claim, while Leyonhjelm is defending his comments by alleging she said words in parliament that were "tantamount" to claiming all men are rapists.
But so far Leyonhjelm has not been able to produce evidence that Hanson-Young made these remarks and Senator Hanson-Young denies making those remarks.
Leyonhjelm was trying again to have the case thrown out, appealing Justice Richard White's decision to uphold the proceedings in November.
His lawyers - the same who initially represented Mark Latham in his recent defamation case - argue that the case would require an examination of words spoken in Parliament, which would breach parliamentary privilege - a rule granting legal immunity for statements made in parliament. Justice Anthony Besanko upheld the initial judgement.
Senator Leyonhjelm has been ordered to pay Ms Hanson-Young's legal costs incurred during the appeal, which Ms Hanson-Young's lawyer Rebekah Giles told The Feed could amount to $100,000.
Ms Giles said she welcomes the decision.
"I look forward to getting back to the job of preparing for the trial," she said.
Defamation proceedings are due to begin in April.
